Nearly four years after the U.S.-led invasion, the relentless violence is freezing the lives of young Iraqis, and leaving their futures in doubt.

By Sabrina Tavernise in Baghdad

In a dimly lighted living room in central Baghdad, Noor is a lonely teenage prisoner. At 19, he is neither working nor in college. He is not even allowed outdoors.

Nearly four years after the overthrow of Saddam Hussein, the relentless violence is hitting young Iraqis hard. In Baghdad, many young people say that their lives have shrunk to the size of their bedrooms, their dreams packed away and largely forgotten.

This summer, the U.S. military began the most systematic series of sweeps of Baghdad since the war began, trying to make the worst neighborhoods safe for a return to normal life. But the violence between Iraq's two Muslim sectsthe Sunnis and the Shiitescontinues at a frantic pace, prompting a growing number of Baghdad residents to flee. (The Iraqi population is estimated to be 60 percent Shiite Arabs, 20 percent Sunni Arabs, and 20 percent Kurds.)

For Noor, a secular Sunni from a solidly middle-class family, the speed of descent has been breathtaking. After plans to move to the safety of northern Iraq failed, he now spends most days in his living room on the computer. He wants to enroll in collegehe even had one of his friends sneak him an applicationbut his parents won't let him go. Campuses are volatile mixes of sects and ethnicities where sectarian killings have become common.

In the space of a week in October, a Sunni geology professor was gunned down, and the dean of Baghdad University's economics department, a Shiite, was slain along with his family. Last month, dozens of employees at an education ministry office were kidnapped in a daytime raid. (Some were reportedly released within a day.)

Victimsand Perpetrators

As recently as a year ago, most Iraqis dismissed fears of civil war. Iraqis of different sects had always mixed, they said, and no amount of bombing would change that. But the sectarian violence has escalated so much this year that few still cling to that belief.

Young people are not only victims of the violence, they are often involved in it: Most of the perpetrators (and casualties) in the sectarian killings are young men, and with few jobs and little hope for justice through the government, armed gangs and militias can be alluring for young people of both sects.

Safe, a 21-year-old Sunni, is part of his neighborhood-watch group. Three nights a week, he stands guard with a machine gun to protect his block in the ravaged neighborhood of Dora. In the past two years, it's become one of the most lethal areas for Shiites, who report brutal killings for offenses as minor as pinning up posters of Shiite saints in shops. Now, few Shiites remain.

Safe has recently attended more than a dozen funerals for Sunnis who have been killed. He fears Shiite death squads and policemen.

As neighborhoods in Baghdad grow increasingly divided into a Shiite east and a Sunni west along the Tigris River, opportunities for young Shiites and Sunnis to mix are dwindling.

Ali Wahid, 27, works near Sadr City, Baghdad's largest Shiite district, on a water project that is part of the American reconstruction effort. He would never go west of the Tigris, where Sunni neighborhoods are deadly for Shiites like him. A friend says he has not left the neighborhood in two years.

Ali says his life has improved since the U.S.-led invasion. His job has allowed him to pay off debts, buy a house, and even afford to marry. But in some ways, he says, relations were easier when Saddam was in power, because as the ruling class, the Sunnis were less likely to lash out at the Shiites.

"Before, I could joke with Sunnis about Saddam,'' he says. "Now, if I talk against him, I'm afraid they might hurt me later in a secret way.''

No More Basketball

At the Sharqiya Secondary School, a girls' school in Baghdad once known for its basketball team, after-school sports are no longer offered; parents say the security situation is too risky. And enrollment rates are down; the school used to get 150 new students a year, but this year it has about 60.

Like many students here, Sara, a 10th-grader with perfect English and straight A's, had planned on going to college, but her parents will no longer allow it.

"The future is totally unclear for me now," she says, standing in the school courtyard.

In a conversation later, Sara confides that her family is trying to leave the country, and that if they can't get out, she would think seriously about marrying straight out of high school.

Her mother married at 24, after she had earned a degree in civil engineering. "Their time was different in a thousand ways," she says. "There's no dream for me. I really, really want to leave Iraq.''